[Microbiological study of nosocomial lung infections].

A total of 83 adult patients between 25 and 60 years of age who acquired pulmonary infectious disease within 48 hours after being admitted to the medical, surgical and/or intensive care units at the university hospital of the "Universidad de Los Andes" (Mérida, Venezuela) were studied during a period of 18 months. The most frequent clinical entity observed was pneumonia (49.4%). In all types of pulmonary samples obtained by secretion or puncture, more than half gave positive results to the microbiological analysis. Gram-negative bacilli prevailed as the etiological agents, with a preponderance of the species from Klebsiella (21.7%) and Pseudomonas (15.1%) genus. Staphylococcus aureus was also isolated in 13.3% of all cases. Satisfactory sensitivity to third generation cephalosporins and aminoglucosides was observed on these strains. Quinolones showed the highest antimicrobial activity. The application of an adequate antimicrobial therapy, according to the antibiotics sensitivity test results, allowed a successful clinical efficacy in 67.4% of all cases.